Process for improving the fastness to washing of dyed cellulosic textile materials



either as such, or more Patented Nov. 14, 1944 PROCESS FOR MPROVING THEFASTNESS T WASHING OF CELLULOSIG TEX- TILE MATERIALS James HutchisonMacGr egor, Bocking, Braintree,

England, assignor to Courtaulds Limited, London, England, a Britishcompany No Drawing. Application January-23, 1942, Se-

Great Britain December rial No. 428,012. In

4 Claims.

This inventionrelates to the treatment of cellulosic textile materialand in particular to improving the'fastness to washing, without greatlyimpairing the fastness to light or altering the original shade of thesaid material which has been dyed with'a direct cotton dyestuff, and at.the same time giving it. a softer silkier handle and appearance.

I have found that the fastness to washing of cellulosic textilematerials dyed with direct cotton dyestuffs is improved by treating thedyed material with a solution containing formaldehyde and anarylguanidine or a guanidine salt of an aliphatic dicarboxylic'acid or.a guanidine salt of an alkyl ester of an aliphatic dicarboxylic acid,

probably in the form of, their water-soluble condensate, and thenconverting the mixture or the soluble condensate into an insolublecondensate, for instance by heating to a temperature of 140 centigradein the presence of an acidcatalyst. In the case of the guanidine saltsof aliphatic dicarboxylic acids and of alkyl esters of aliphaticdicarboxylic acids the condensation with formaldehyde can, if 'desired,be carried out in neutral or alkaline media. As an example of anarylguanidine which can be used according to this invention, I mentiondiphenylguanidine cm..NH-c'NHctHt It. v Examples of guanidine salts ofaliphatic dicarboxylic acids are guanidine adipate and guanidinesebacate, while as an example of a guanidine salt of an alkyl ester ofan aliphatic dicarboxylic acid I would mention the guanidine salt ofethyl adipate. The treatment can, if desired, be carried out in thepresence of other water-soluble condensates such for instance asurea-formaldehyde, thiourea-formaldehyde and melamineformaldehyde.

When carrying out the process of the present invention I have found thatit is desirable to avoid the use of a large excess of formaldehyde.

The following examples illustrate the invention Rigan Sky Blue G (Soc.Chem. Ind. Basle) is im-- mersed therein and after saturation the fabricis removed from the bath and squeezed evenly and is placed in a pinstenter frame and dried at just under 100 centigrade; it is then heatedat 140 'centigrade for minutes. The resultant fabric has a good fastnessto light, an improved fastness to washing and a soft silk-like handleand appearance.

Example 2 in 30 cubic centimetres of 80 per cent acetic acid and thissolution is added to 100 grams of the urea-formaldehyde condensateprepared above and mixed with suflicient distilled water to make 1 litreof solution. A sample of an all viscose satin fabric which has been dyedwith Rigan Sky Blue G is immersed therein and after soaking is removedfrom the solution and squeezed evenly. The fabric but they are not to beconsidered aslimiting it in any way.

Example! 7 30 grams of diphenilguanidine are dissolved by warming with30 cubic-centimetres of per cent acetic acid. 160 cubic centimetres of40 per cent formaldehyde are-added with sufllcient distilled";

water to make 1 litre of solution. A sample of an:

all viscose rayon fabric which has been dyed with at rlcis placed justunder placed in a pin stenter frame and dried at just under100centigr'ade. It is then heated at centigrade for 15 minutes to form theinsoluble condensation product. During this heating a part of theformaldehyde is split off from the urea-formaldehyde condensate andcombines with the diphenylguanidine. The fastness to'light and thefastness to washing of the dyed treated material are found to beimproved. r

If desired, a soluble diphenylguanidine-formaldehyde condensate may besubstituted for the diphenylguanidine in this example.

Example 3' 30 grams of guanidine' sebacate are dissolved in a littlewarm water, the resulting solution cooled, 200 cubic centimetres of 40per cent formaldehyde added and the whole diluted with distilled waterto make 1 litre of solution. The pH of the solution is then adjusted to8.0; A sample of an all viscose satin fabric which has been dyed withRigan Sky Blue G (Soc. of Chem. Ind. Basle) is immersed therein andafter soaking is removed from the solution and squeezed evenly. I Thefabin a pin stenter frame and dried at centlgrade. It is finally heatedat 140 centigrade for 15 minutes \to form the insoluble condensationproduct. The resultant fabric possesses a soft silky handle, has verygood fastness to light and is extremely fast to washing, for examplewhen a piece of the fabric of dimensions 4" x a" and a piece of whiteundyed fabric of dimensions 2" .x 2" are treated in 70 cubic centimetresof a 0.2 per cent soap solution for 90 minutes at 60 centigrade, thefabrics removed and rinsed with distilled water the white piece remainsunstained while the shade of the dyed piece is unchanged.

" Example 4 30 grams of guanidine adipate are dissolved in a little warmWater, the solution cooled and 200 1 cubic centimetres of 40 per centformaldehyde added. Just before use 10 grams of ammonium sulphatedissolved in a little water are added and the whole bulked to 1 litrewith distilled water.

A length of an all viscose satin fabric which has What I claim is:

1. The process of improving the fastness to washing of cellulosictextile materials dyed with direct cotton dyestuffs and imparting a softsilks, handle thereto, by treating the dyed material with a solutioncontaining a watersoluble condensate of formaldehyde with a substanceselected from the group consisting of an arylguanidine, a guanidine saltof an aliphatic dicarboxylic acid and a guanidine salt of an alkyl esterof an aliphatic dicarboxylic acid, and then converting the solublecondensate into an insoluble condensate.

2. The process of improving the fastness to washing of cellulosictextile materials dyed with direct cotton dyestuffs and imparting a softsilky handle thereto, by treating the dyed material with a solutioncontaining formaldehyde and a. substance selected from the groupconsisting of an arylguanidine, a guanidine salt of an aliphaticdicarboxylic acid and a guanidine salt of an alkyl ester of an aliphaticdicarboxylic acid, and then converting the said mixture into aninsoluble condensate.

8. A process as claimed in claim 1 in which the insoluble condensate isformed by heating in the presence of an acid catalyst.

4. A process as claimed in claim 2 in which the insoluble condensate isformed by heating in the presence of an acid catalyst.

. JAS. H. MACGREGOR.

